Create zap objects
zap() creates a sentinel object that indicates that an object
should be removed. For instance, named zaps instruct env_bind()
and call_modify() to remove those objects from the environment or
the call.
The advantage of zap objects is that they unambiguously signal the
intent of removing an object. Sentinels like NULL or
missing_arg() are ambiguous because they represent valid R
objects.
zap() is_zap(x)
x |
An object to test. |
# Create one zap object:
zap()
# Create a list of zaps:
rep(list(zap()), 3)
rep_named(c("foo", "bar"), list(zap()))Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.